Carr was scrambling around to avoid the pass rush when he ran forward. Carr was going down and was hit high by Denver Broncos lineman Adam Gotsis. Carr’s torso bent forward and he immediately reached for his back.

Oakland Raiders quarterback Derek Carr left Sunday’s game against the Broncos early with an injury. (AP)

Carr was down for a few moments, but eventually walked off under his own power. EJ Manuel replaced him at quarterback. After Manuel finished out the series, Carr walked back to the locker room gingerly.

Raiders coach Jack Del Rio said Carr’s back tightened up and made it sound like this won’t be a long-term issue.

Jack Del Rio on Derek Carr: "His back spasmed up. That's what it was. … I'm not a doctor." But not concerned long term based on what told.

It was a strange coincidence that Tony Romo was calling the game for CBS. Romo was tackled on a similar play last year, in which he was tackled and bent forward in the preseason and injured his back. Romo would never start a game for the Cowboys again.

It was a bad flashback for Raiders fans. Last season Carr was tackled in an awkward way late in the season against the Indianapolis Colts, and broke his leg. The Raiders completely fell apart without him in Week 17 and a playoff game against the Houston Texans.

The Raiders had Super Bowl hopes this season, but that’s obviously centered around Carr, who briefly became the highest paid player in NFL history this summer. Now the Raiders need to hope their franchise quarterback is OK, or their season could go sour quickly.